<template>
  <div class="goods-image">
    <!-- 大图 -->
    <div
      class="large"
      v-show="show"
      :style="[{ backgroundImage: `url(${images[currIndex]})` }, largePosition]"
    ></div>
    <!-- 中图-->
    <div class="middle" ref='target' >
      <img :src="images[currIndex]" alt="" />
      <!-- mark -->
      <div class="layer_goods" v-show="show" :style="layerPosition" ></div>
    </div>
    <!-- 小图 -->
    <ul class="small">
      <li
        v-for="(img, i) in images"
        :key="img"
        :class="{ active: i === currIndex }"
      >
        <img @mouseenter="currIndex = i" v-lazy="img" alt="" />
      </li>
    </ul>
  </div>
</template>
<script>
import { reactive, ref, watch } from "vue";
import {useMouseInElement} from '@vueuse/core'

export default {
  name: "GoodsImage",
  props: {
    images: {
      type: Array,
      default: () => [],
    },
  },
  setup(props) {
    const currIndex = ref(0);
    // 是否显示遮挡罩 和大图
    const show = ref(true);
    // 遮罩的坐标
    const layerPosition = reactive({
        left:0,
        top:0
    })
    // 大图背景样式
    const largePosition = reactive({
      backgroundPositionX: '100px',
      backgroundPositionY: 0
    });

    // 监听鼠标是否进入放大镜区域
    const target = ref(null)
    // isOutside  进去 false  外面 true
    const {elementX, elementY, isOutside} = useMouseInElement(target)
    watch([elementX, elementY, isOutside], ([x,y,out])=>{
        // console.log(elementX.value, elementY.value, isOutSize.value);
        show.value = !out
        const position = {x:0,y:0}
        // x轴
        if(x<100) position.x = 0;
        else if(x>300) position.x = 200;
        else position.x = x - 100
        // y轴
        if(y<100) position.y = 0;
        else if(y>300) position.y = 200;
        else position.y = y - 100

        // 样式修改
        // mark
        layerPosition.left = parseInt(position.x) + 'px'
        layerPosition.top = parseInt(position.y) + 'px'
        // 大图
        largePosition.backgroundPositionX = -2 * position.x + 'px'
        largePosition.backgroundPositionY = -2 * position.y + 'px'
    })

    return { currIndex, layerPosition, largePosition, show, target };
  },
};
</script>
<style scoped lang="less">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;
  z-index: 500;
  .large {
    position: absolute;
    top: 0;
    left: 412px;
    width: 400px;
    height: 400px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    background-repeat: no-repeat;
    background-size: 800px 800px; // 原来的两倍
    background-color: #f8f8f8;
  }
  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
    position: relative;
    cursor: move;
    .layer_goods {
      width: 200px;
      height: 200px;
      // opacity: 1;
      background: rgba(0, 0, 0, 0.2);
      // z-index: 2000;
      position: absolute;
    }
  }
  .small {
    width: 80px;

    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;
      &:hover,
      &.active {
        border: 2px solid @xtxColor;
      }
    }
  }
}
</style>